Phlebotomy device having temperature sensor for detecting flashback

ABSTRACT

A phlebotomy device includes a needle defining a lumen and having a proximal end portion and a distal end portion. The distal end portion includes a sharpened tip configured to pierce tissue. The phlebotomy device further includes a sensor disposed at least partially within the lumen. The sensor has a first state and a second state and is configured to transition from the first state to the second state upon exposure to blood at physiological temperature.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 12/212,184 filed Sep. 17, 2008, which claimedpriority to U.S. Patent Application 60/995,588, filed on Sep. 27, 2007,both of which are incorporated by reference in their respectiveentireties.

BACKGROUND

The present disclosure relates to medical needles. More particularly,the present disclosure relates to phlebotomy needles with a flashbacksensor.

Phlebotomy is the process of removing blood for a variety of medical andscientific purposes. This process entails the penetration of a humanvein by a medical device containing a hollow needle to draw blood.Phlebotomy is an invasive procedure and, when conducted improperly, maylead to infection or physical trauma at the penetration site, or it maysimply fail to yield a sufficient quantity of blood. Therefore,healthcare personnel, including medical students, nurses, and healthcaretechnicians, require training to properly use a medical device during aphlebotomy.

The state of the art contains numerous examples of medical devicesadapted to draw blood from patients. These devices include standardneedle-syringes, butterfly needle sets, and phlebotomy needles.Typically, a butterfly needle set includes a hollow needle having asharpened distal end and a proximal end. The proximal end of the hollowneedle is secured to a needle hub. In turn, a proximal portion of theneedle hub is connected to flexible tubing. The needle hub defines afluid conduit communicating with the tubing and includes a pair offlexible, radially extending wings that facilitate grasping of thebutterfly needle set by medical personnel. Generally, the flexibletubing is formed of a transparent material that allows medical personnelto visualize blood flow, i.e., flashback, through the tubing immediatelyproximal to the needle hub. Visualization of flashback permits medicalpersonnel to confirm that the needle has been properly inserted into apatient.

Generally, phlebotomy needles do not include structures for sensing orvisualizing flashback. Although the lack of a structure for visualizingflashback in phlebotomy needles is not a major drawback for moreexperienced medical personnel, for those having little experiencedrawing blood with phlebotomy needles, the lack of any means to confirmthat the needle has been properly positioned within a patient mayincrease the time required to draw blood and add to the discomfort ofthe patient.

In an attempt to overcome the above disadvantages, U.S. Pat. No.5,450,856 to Norris discloses a phlebotomy needle attached to a bloodcollection tube. This phlebotomy needle includes an outboard needle, aninboard needle and a bulb therebetween. The bulb is clear and allowsmedical personnel to visualize blood within the bulb when the outboardneedle has been properly positioned within the vein of a patient. Thebulb also includes a button that can be depressed by medical personnelto vent air from within the needle. Air within the needle prevents bloodfrom flowing through the needle and must be vented.

U.S. Patent Application 60/877,937 by Weilbacher et al. (“Weilbacher”),filed on Dec. 29, 2006, also discloses a phlebotomy needle including astructure that permits visualization of flashback. This phlebotomyneedle includes a distal needle portion, a proximal needle portion and acentral needle portion. The central needle portion defines an openingand a fluid channel in communication with the opening. The phlebotomyneedle additionally includes a material positioned adjacent to theopening. This material allows passage of air through the opening to exitthe fluid channel while preventing passage of blood. In addition, thematerial enables visualization of blood flow.

Although the Norris and Weilbacher phlebotomy needles facilitatevisualization of flashback, a need exists for other apparatus andmethods for sensing flashback during phlebotomy.

SUMMARY

The present invention relates to a phlebotomy device including a needledefining a lumen and having a proximal end portion and a distal endportion. The distal end portion includes a sharpened tip configured topierce tissue. The phlebotomy device further includes a sensor disposedat least partially within the lumen. The sensor has a first state and asecond state, and is configured to transition from the first state tothe second state upon exposure to blood at physiological temperature.

In one embodiment, the sensor is made of shape memory alloy.

In one embodiment, the sensor is made of nickel-titanium alloy.

In one embodiment, the sensor is a wire.

In one embodiment, the sensor has a proximal end portion and a distalend portion having a generally helical shape.

In one embodiment, the sensor has a proximal end and a distal end fixedwithin the lumen of the needle.

In one embodiment, the phlebotomy device further includes a needleholder supporting the needle.

In one embodiment, the needle holder defines a cavity, wherein thedistal end portion of the needle extends outwardly from the cavity andthe proximal end portion of the needle is supported within the cavity.

In one embodiment, the phlebotomy device further includes a deformablevalve positioned about the proximal end portion of the needle.

In one embodiment, the deformable valve includes a tubular section, anindicator, and a weakened wall section connecting the tubular sectionand the indicator.

In one embodiment, the indicator is made of an elastomeric material.

In one embodiment, the deformable valve is configured to move between afirst collapsed position to a second extended position upon transitionof the sensor from the first state to the second state.

In one embodiment, the sensor extends proximally when transitioning fromthe first state to the second state.

In one embodiment, the sensor contacts the deformable valve to move thedeformable valve from the first collapsed position to the secondextended position as the sensor transitions from a first state to thesecond state.

In an alternate embodiment, the phlebotomy device includes a needlehaving a distal needle portion and defining a lumen extendingtherethrough a sensor disposed within the lumen, the sensor being fixedto the distal needle portion and having a non-linear portion. Thenon-linear portion of the sensor transitions to a substantially linearstate when in contact with blood at physiological temperature.

In one embodiment, the non-linear portion has a sinusoidalconfiguration.

In one embodiment, the non-linear portion has a helical configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed phlebotomy device aredescribed herein with reference to the drawings:

FIG. 1 is a cross-sectional view of an embodiment of the presentlydisclosed phlebotomy device; and

FIG. 2 is a cross-sectional view of the phlebotomy device shown in FIG.1 inserted into a vein.

DETAILED DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed phlebotomy device will now bedescribed in detail with reference to the drawings wherein likereference numerals designate identical or corresponding elements in eachof the several views. In the description that follows, the term“proximal,” as is traditional, will refer to the end of the phlebotomydevice that is closer to the operator, while the term distal will referto the end of the device that is farther from the operator.

FIGS. 1 and 2 illustrate an embodiment of the presently disclosedphlebotomy device 10 adapted to draw blood from a patient. Generally,phlebotomy device 10 includes a needle 12, a sensor 14, and a needleholder 16. Sensor 14 is supported within needle 12. Needle holder 16supports needle 12 and is configured to receive a blood collection tube(not shown).

Needle holder 16 includes a body 24. Although the drawings show a body24 having a cylindrical shape, the present disclosure envisions bodieswith other configurations. Body 24 defines a cavity 26 adapted toreceive a blood collection tube (not shown). In addition, body 24includes proximal and distal ends 19, 20. Proximal end 19 has an openingadapted to receive a blood collection tube (not shown) and distal end 20of body 24 is operatively coupled to a portion of needle 12. In oneembodiment, distal end 20 includes an engagement portion 22 tofacilitate connection of needle 12 to needle holder 16. Engagementportion 22 may include a female fitting configured to engage a malefitting on needle 12. Alternatively, engagement portion 22 may includeother engagement structures such as screws threads, snap-typeconnectors, luers or any other suitable connecting structure. In analternate embodiment, needle 12 is fastened to engagement portion 22using an adhesive. A coupling section 28 of engagement portion 22extends proximally into cavity 26 of needle holder 16. Coupling section28 facilitates connection between needle holder 16 and a deformablevalve 18.

As discussed above, deformable valve 18 is operatively connected tocoupling section 28 of needle holder 16 such as with adhesives or bywelding or by an interference or snap-type fit. Body 24 of needle holder16 surrounds deformable valve 18. Deformable valve 18 functions to sealand reseal the proximal portion 30 of needle 12 prior to and afterremoval of a blood collection tube (not shown) from needle holder 16. Inparticular, deformable valve 18 includes a tubular section 32surrounding proximal needle portion 30, an indicator 34, and a wallsection 36 connecting tubular section 32 and indicator 34. Wall section36 is weaker than tubular section 32 and indicator 34. In oneembodiment, wall section 36 is formed by a thinner cross-section ofmaterial in relation to the cross-section of tubular section 32 andindicator 34, as shown in FIG. 1. Indicator 34 is made of an elastomericmaterial or any other suitable resilient material. In operation,indicator 34 is moved from a first collapsed position (see FIG. 1) to asecond extended position (see FIG. 2) by sensor 14 when needle isproperly inserted in vasculature V of a patient.

Needle 12 is mounted to engaging portion 22 of needle holder 16. Aspreviously discussed, deformable valve 18 surrounds proximal needleportion 30 of needle 12. Proximal needle portion 30 has a proximalopening 44 and a sharpened proximal tip 43. Sharpened proximal tip 43 isadapted to pierce deformable valve 18 and a stopper of a bloodcollection tube when the blood collection tube is positioned in needleholder 16. In addition to proximal needle portion 30, needle 12 also hasa distal needle portion 38 and defines a lumen 40 extendingtherethrough. Distal needle portion 38 includes a distal opening 45 anda sharpened distal tip 42 configured to pierce tissue. Distal opening 45and proximal opening 44 define the ends of lumen 40. At least a portionof needle 12 may be coated with or made from an insulating material suchas a polymer or ceramic.

Sensor 14, which may be a wire or any other suitable apparatus, isdisposed at least partially within lumen 40 and includes a proximal endportion 46 and a portion 48 a. While proximal end portion 46 of sensor14 has a general elongate configuration, portion 48 a has an extendedconfiguration in its natural state. Alternatively, the portion 48 a ofthe sensor 14 may be positioned anywhere along the length of sensor 14.As illustrated in FIG. 1, portion 48 a may have a generally wave-like orsinusoidal shape. Other configurations are envisioned including, forexample, helical configuration. A distal end 50, or any other portion ofsensor 14, may be fixed to the distal needle portion 38 within lumen 40such as by welding, crimping, adhesives, or the like. Proximal endportion 46 of sensor 14 has a proximal end 52, which is not attached toneedle 12. Proximal end 52 of sensor 14 may be blunt or configured toprevent piercing of deformable valve 18. In one embodiment, proximal end52 of sensor 14 may be resilient. During use, a resilient proximal end52 of sensor 14 moves distally when a blood collection tube ispositioned within cavity 26 of body 24 of needle holder 16, therebypreventing the piercing of deformable valve 18 by sensor 14.

During use, sensor 14 serves as a flashback sensor by transitioning froma first state to a second state upon exposure to blood at physiologicaltemperature. To this end, sensor 14 may be made of a shape memory alloy,such as nickel titanium, or any other suitable material. In the firststate, portion 48 a of sensor 14 has a contracted configuration andproximal end 52 of sensor 14 is positioned such that indicator 34 is itsfirst collapsed position (FIG. 1). In the depicted embodiment, portion48 a maintains a contracted configuration at about room temperature.When phlebotomy needle 12 is inserted into the vasculature V (FIG. 2) ofa patient and sensor 14 contacts blood at about physiologicaltemperature, sensor 14 transitions to a second state and theconfiguration of portion 48 a is modified moving towards proximal needleportion 30. In one embodiment, portion 48 a of sensor 14 becomessubstantially linear when sensor 14 contacts blood at physiologicaltemperature. Although the drawings show portion 48 a of sensor 14 havinga substantially linear shape when in contact with blood at aboutphysiological temperature, it envisioned that portion 48 a of sensor 14may have other extended shapes when exposed to blood at aboutphysiological temperature. In the case of a shape memory alloy sensor14, portion 48 a undergoes a phase transformation and attempts to returnto its original crystallographic configuration upon contact with bloodat physiological temperature. Since the distal end 50 of structure 14 isfixed to distal needle portion 38, the modification of portion 48 acauses proximal end 52 of sensor 14 to move in a proximal direction. Asproximal end 52 moves proximally, sensor 14 contacts deformable valve 18and moves indicator 34 of valve 18 to the second extended position, asdepicted in FIG. 2. The change in position of indicator 34 of deformablevalve 18 signals to the healthcare professional that a vein has beenproperly accessed. As will be discussed below, the modified shape ofportion 48 a of sensor 14 is configured to maintain a contractedconfiguration such as wave-like or helical configuration.

In operation, healthcare professionals employ phlebotomy device 10 todraw blood from a patient. Phlebotomy device 10 is also capable ofsensing flashback. Initially, healthcare professionals identifyvasculature V, e.g., vein, and place a tourniquet around the areasurrounding the identified vasculature V. The skin about the vasculatureshould then be palpated to determine the size, depth, and direction ofthe vasculature. The healthcare professional should subsequently cleanthe skin area around the vasculature V. At this moment, sensor 14 is inthe first state. In the first state, portion 48 a of sensor 14 has acontracted configuration and proximal end 52 of sensor 14 is positionedsuch that indicator 34 is its first collapsed position, as seen in FIG.1.

After preparing the patient for the phlebotomy procedure, the healthcareprofessional inserts distal needle portion 38 into the vasculature V ofthe patient to draw blood from the patient. The sharpened tip 42 ofdistal needle portion 38 pierces the wall of the vein V. At this time,blood B enters lumen 40 through distal opening 45 of needle 12. Theblood flows through lumen 40 and contacts sensor 14. Upon exposure toblood at about physiological temperature, sensor 14 transitions to thesecond state and the configuration of portion 48 a is modified. In oneembodiment, sensor 14 expands as it transitions to the second state.Since distal end 50 of sensor 14 is fixed within lumen 40, the proximalend 52 of sensor 14 moves proximally. As proximal end 52 movesproximally, sensor 14 contacts deformable valve 18 and moves indicator34 of deformable valve 18 to the second extended position, asillustrated in FIG. 2. In the second extended position, deformable valve18 signals to the healthcare professional that flashback has beenachieved.

Deformable valve 18 also serves as a seal. Before positioning the bloodcollection tube within cavity 26 of body 24, deformable valve 18 sealsproximal needle portion 30. When the blood collection tube is insertedinto cavity 26, proximal needle portion 30 engages a stopper (not shown)of the blood collection tube and pierces through the stopper. Indicator34 and sensor 14 are compressed downwardly as proximal needle portion 30pierces the stopper of the blood collection tube and enters a cavityinside the blood collection tube. The blood collection tube ismaintained at a vacuum such that when distal needle portion 38 isproperly positioned in the vasculature V of the patient and the bloodcollection tube is positioned within cavity 26, blood flows throughlumen 40 of needle 12 into the blood collection tube. When the bloodcollection tube is removed from needle holder 16, sensor 14 andindicator 34, which are resilient, return to their second stateconfiguration and deformable valve 18 covers proximal needle portion 30to seal proximal opening 44 of needle 12.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, portion 48 a of sensor 14 mayhave a sinusoidal wave or helical configuration in its natural state. Inaddition, needle holder 16 may include flanges at its proximal end tofacilitate handling of phlebotomy device 10. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of the embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

Having described the invention in detail, it will be apparent thatmodifications and variations are possible without departing from thescope of the invention defined in the appended claims.

When introducing elements of the present invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the”, and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including”, and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above constructions, products,and methods without departing from the scope of the invention, it isintended that all matter contained in the above description and shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

1. A phlebotomy device comprising: a needle having a proximal end, asharp distal end opposite the proximal end, and a lumen extendingbetween the proximal end and the distal end; and an elongate sensorpositioned at least partially in the lumen and connected to the needle,the sensor having a proximal end free from direct connection to theproximal end of the needle, a distal end opposite the proximal end, afirst length measured between the proximal end and the distal end whenthe sensor is at a first temperature, and a second length longer thansaid first length when the sensor is at a second temperature higher thansaid first temperature so that the proximal end is positioned moreproximally when subjected to said second temperature than when subjectedto said first temperature.
 2. A phlebotomy device as set forth in claim1 wherein the distal end of the sensor is connected directly to thelumen.
 3. A phlebotomy device as set forth in claim 1 wherein the sensorcomprises a curved portion.
 4. A phlebotomy device as set forth in claim3 wherein the curved portion is sinusoidal.
 5. A phlebotomy device asset forth in claim 1 wherein the sensor comprises a shape memory alloy.6. A phlebotomy device as set forth in claim 1 wherein said secondtemperature comprises a physiological temperature.
 7. A phlebotomydevice as set forth in claim 1 wherein the sensor comprises a wire.
 8. Aphlebotomy device as set forth in claim 1 further comprising a needleholder supporting the needle and having a hollow cavity, the proximalend of the sensor extending into the hollow cavity of the needle holderwhen the sensor is subjected to said second temperature.